DIMMER SYSTEM AND DAMPER CIRCUIT THEREOF

• US 20120319608A1
• Filed: 09/22/2011
• Published: 12/20/2012
• Est. Priority Date: 06/16/2011
• Status: Active Grant

• Current Assignee: Delta Electronics Company Limited (Delta Electronics Incorporated)
• Original Assignee: Delta Electronics Company Limited (Delta Electronics Incorporated)
• Inventors: XU, Li-Zhi, ZHANG, Wei-Qiang, ZHANG, Qi
• Granted Patent: US 8,710,758 B2
• Time in Patent Office: Days
• US Class Current: 315/208
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 5/257 using semiconductor devices only
• CPC Class Codes: H05B 45/36 Circuits for reducing or suppressing harmonics, ripples or electromagnetic interferences [EMI]

Abstract

A damper circuit is operable to dampen resonance of an electromagnetic interference filter when a phase dimmer activates. The damper circuit includes a capacitor and a bipolar junction transistor (BJT). The capacitor includes a first terminal and a second terminal. The BJT includes a control terminal, a collector terminal, and an emitter terminal. The control terminal of the BJT receives a control signal to make the BJT operate in the amplified area, and the collector terminal of the BJT is electrically connected to the second terminal of the capacitor. The first terminal of the capacitor receives the resonance generated to by the electromagnetic interference filter, and the BJT and the capacitor cooperate to dampen the resonance generated by the electromagnetic interference filter when the BJT operates in the amplified area.

Claims

1. A damper circuit for dampening resonance generated by an electromagnetic interference filter when a phase dimmer activates, the damper circuit comprising:

a capacitor comprising a first terminal and a second terminal; and

a bipolar junction transistor comprising a control terminal, a collector terminal, and an emitter terminal, wherein the bipolar junction transistor is operable to receive a control signal through the control terminal thereof to operate in the amplified area, and the collector terminal of the bipolar junction transistor is electrically connected to the second terminal of the capacitor,

wherein the first terminal of the capacitor is operable to receive the resonance generated by the electromagnetic interference filter, and the bipolar junction transistor and the capacitor operate together to dampen the resonance generated by the electromagnetic interference filter when the bipolar junction transistor operates in the amplified area.

2. The damper circuit according to claim 1, wherein the damper circuit further comprises:

a diode connected between the collector terminal and the emitter terminal of the bipolar junction transistor in the reverse direction.

3. The damper circuit according to claim 1, wherein the damper circuit further comprises:

a resistor comprising a first terminal and a second terminal, wherein the first terminal of the resistor is electrically connected to the second terminal of the capacitor, and the second terminal of the resistor is electrically connected to the control terminal of the bipolar junction transistor.

4. The damper circuit according to claim 2, wherein the damper circuit further comprises:

a power switch comprising a control terminal, a first terminal, and a second terminal, wherein the first terminal of the power switch is electrically connected to the second terminal of the resistor, the second terminal of the power switch is electrically connected to the control terminal of the bipolar junction transistor, and the control terminal of the power switch is operable to receive the control signal so as to make the bipolar junction transistor operate in the amplified area.

5. A damper circuit for dampening resonance generated by an electromagnetic interference filter when a phase dimmer activates, the damper circuit comprising:

a capacitor comprising a first terminal and a second terminal; and

a bipolar junction transistor comprising a control terminal, a collector terminal, and an emitter terminal, wherein the bipolar junction transistor is operable to receive a control signal through the control terminal thereof to operate in the amplified area, and the emitter terminal of the bipolar junction transistor is electrically connected to the second terminal of the capacitor,

wherein the first terminal of the capacitor is operable to receive the resonance generated by the electromagnetic interference filter, and the bipolar junction transistor and the capacitor operate together to dampen the resonance generated by the electromagnetic interference filter when the bipolar junction transistor operates in the amplified area.

6. The damper circuit according to claim 5, wherein the damper circuit further comprises:

a diode connected between the collector terminal and the emitter terminal of the bipolar junction transistor in the reverse direction.

7. The damper circuit according to claim 5, wherein the damper circuit further comprises:

a resistor comprising a first terminal and a second terminal, wherein the first terminal of the resistor is electrically connected to the control terminal of the bipolar junction transistor.

8. The damper circuit according to claim 6, wherein the damper circuit further comprises:

a power switch comprising a control terminal, a first terminal and a second terminal, wherein the first terminal of the power switch is electrically connected to the second terminal of the resistor, and the control terminal of the power switch is operable to receive the control signal so as to make the bipolar junction transistor operate in the amplified area.

9. A dimming system, comprising:

a phase dimmer for regulating a phase of an alternating current voltage to generate a modulated alternating current voltage;

an electromagnetic interference filter electrically connected to the phase dimmer for filtering the electromagnetic interference signal generated by the phase dimmer;

a converter electrically connected to the electromagnetic interference filter for transforming the modulated alternating current voltage into a modulated direct current voltage;

a damper circuit electrically connected to the converter for dampening resonance generated by the electromagnetic interference filter when the phase dimmer activates; and

a power converter electrically connected to the damper circuit for transforming the modulated direct current voltage.

10. The dimming system according to claim 9, wherein the damper circuit comprises:

a capacitor comprising a first terminal and a second terminal; and

a bipolar junction transistor comprising a control terminal, a collector terminal, and an emitter terminal, wherein the bipolar junction transistor is operable to receive a control signal through the control terminal thereof to operate in the amplified area, and the collector terminal of the bipolar junction transistor is electrically connected to the second terminal of the capacitor,

wherein the first terminal of the capacitor is operable to receive the resonance generated by the electromagnetic interference filter, and the bipolar junction transistor and the capacitor operate together to dampen the resonance generated by the electromagnetic interference filter when the bipolar junction transistor operates in the amplified area.

11. The dimming system according to claim 10, wherein the damper circuit further comprises:

a diode connected between the collector terminal and the emitter terminal of the bipolar junction transistor in the reverse direction.

12. The dimming system according to claim 11, wherein the damper circuit further comprises:

a resistor comprising a first terminal and a second terminal, wherein the first terminal of the resistor is electrically connected to the second terminal of the capacitor, and the second terminal of the resistor is electrically connected to the control terminal of the bipolar junction transistor.

13. The dimming system according to claim 12, wherein the damper circuit further comprises:

a power switch comprising a control terminal, a first terminal, and a second terminal, wherein the first terminal of the power switch is electrically connected to the second terminal of the first resistor, the second terminal of the power switch is electrically connected to the control terminal of the bipolar junction transistor, and the control terminal of the power switch is operable to receive the control signal so as to make the bipolar junction transistor operate in the amplified area.

14. The dimming system according to claim 13, wherein the power switch comprises a bipolar junction transistor.

15. The dimming system according to claim 9, wherein the damper circuit comprises:

a capacitor comprising a first terminal and a second terminal; and

a bipolar junction transistor comprising a control terminal, a collector terminal and an emitter terminal, wherein the bipolar junction transistor is operable to receive a control signal through the control terminal thereof to operate in the amplified area, and the emitter terminal of the bipolar junction transistor is electrically connected to the second terminal of the capacitor,

wherein the first terminal of the capacitor is operable to receive the resonance generated by the electromagnetic interference filter, and the bipolar junction transistor and the capacitor operate together to dampen the resonance generated by the electromagnetic interference filter when the bipolar junction transistor operates in the amplified area.

16. The dimming system according to claim 15, wherein the damper circuit further comprises:

a diode connected between the collector terminal and the emitter terminal of the bipolar junction transistor in the reverse direction.

17. The dimming system according to claim 16, wherein the damper circuit further comprises:

a resistor comprising a first terminal and a second terminal, wherein the first terminal of the resistor is electrically connected to the control terminal of the bipolar junction transistor.

18. The dimming system according to claim 17, wherein the damper circuit further comprises:

a power switch comprising a control terminal, a first terminal and a second terminal, wherein the first terminal of the power switch is electrically connected to the second terminal of the resistor, and the control terminal of the power switch is operable to receive the control signal so as to make the bipolar junction transistor operate in the amplified area.

19. The dimming system according to claim 18, wherein the power switch comprises a bipolar junction transistor.

20. The dimming system according to claim 9, wherein the phase dimmer comprises:

a triode for alternating current switch;

a diode for alternating current switch electrically connected to the triode for alternating current switch;

a variable resistor electrically connected to the diode for alternating current switch;

a resistor connected with the variable resistor in series; and

a capacitor electrically connected to the triode for alternating current switch, the diode for alternating current switch, and the variable resistor.

21. The dimming system according to claim 9, wherein the converter comprises:

a rectifier electrically connected to the electromagnetic interference filter for generating the modulated direct current voltage by rectifying the modulated alternating current voltage; and

a filter electrically connected to the rectifier for filtering the modulated direct current voltage.